Arthroplasty is an orthopedic surgical procedure in which a dysfunctional or arthritic joint surface is replaced, remodeled or redesigned to alleviate pain, restore range of motion or to fix physical joint damage caused by a fracture. Total Hip Replacement (“THR”) surgery, also known as hip arthroplasty, is a surgical procedure wherein the proximal femur, with its femoral head and neck, is removed and a prosthetic device (or stem) having a prosthetic femoral head is implanted into the femur. The acetabulum, or hip socket, is also replaced or modified to accept a cup. The cup is configured to receive the prosthetic head. The prosthetic device (or stem) is typically made of titanium or a titanium alloy. The head may be made of a biocompatible plastic, ceramic or other suitable material. The cup may be made of a biocompatible plastic or other suitable material. The prosthetic device and the cup are typically anchored to the bone with bone cement.
Typically, in THR, the surgeon will take a number of measurements by hand or x-ray scan related to proper selection of the prosthetic device, limb length, and hip rotation. During surgery, after making an incision, the femur is pushed out of socket to expose the joint cavity and the deteriorated or damaged femoral head is removed. The femur is then prepared to receive the stem by cleaning and enlarging the hollow center portion of the bone, thereby creating a cavity that matches the shape of the implant stem. The top end of the femur is planed and smoothed so the stem can be inserted flush with the bone surface. If the head is a separate piece, the proper size is selected and attached. Finally, the head is seated within the cup so the joint is properly aligned and the incision is closed.
Hand measuring techniques and x-ray scans are inaccurate and increase the error rate or potential for error in a THR, and may lead to an improperly positioned prosthetic device. Improper positioning of the prosthetic device can result in a change of leg length, dislocation of the hip or perforation of the femur.
There is a need in the art for a total hip replacement surgical guide tool to aid in properly positioning the prosthetic device that reduces the potential for error and improper positioning in a THR. There is also a need in the art for a method of manufacturing such a surgical guide tool.